Castle and cathedral are situated on the so-called 'old castle hill' above the town of Mersburg
and particularly attractive on account of their many towers and gables.

The cathedral, originally an early romanesque church, was built from 1015 to 1021 under King Henry II. Its current face dates back to Bishop Thilo von Trotha and the early 16th century, ending a long period of continued alteration.

Work on the castle began in 1483, but went on until 1661 when the large and regular, three-winged late renaissance building was finally completed.

The castle gardens are situated to the north and separated from the castle by a moat. In 1661, Duke Christian I of Saxony-Merseburg began the transformation of the castle gardens into a baroque leisure garden. The northern section was later framed by the castle garden salon, which was constructed by Michael Hoppenhaupt from 1727 to 1737. Originally designed as a garden party pavilion, it is still a popular venue for events today.

Parts of the gardens were re-designed in the first half of the 19th century, taking the existing avenues as a main point of reference. Major alterations took place in 1968, when the longitudional axes provided by the footpaths were aligned with the castle garden salon and the transverse axes with Zech Palace (1782) and Assembly House (1892 - 1895).

The garden features pairs of obelisks and a copy of the bronze bust of the Prussian Governor Friedrich Kleist von Nollendorf.

Other points of interest include the equestrian statue of Friedrich Wilhelm III, restored in 1998, and a monument, created in 1816 in the course of the Battle of Nations at Leipzig.